You and Ada have been dating for around 4 years. She went into the relationship saying, and truly believing, that marriage would never be an option. She would never consider it. She didn't want you to be legally tied to an assassin/mercenary/murderer.

But that was before you two were together for years. She was sure you'd leave when things got hard. Be disgusted when she cane home bloody and beaten. Or get scared of her when she had to kill in front of you.

It never happened. And it changed her mindset. She really wanted to murder you. She'd never love anyone like you ever again, let alone find someone like you. She wanted to be tied to you forever.

So she bought you a pretty ring, set up a nice dinner at her apartment. And halfway in, she slid over the ringbox without a word.